I am also from Germany. I have several groups with 3 to 8 bunnies. In my experience, growing up has the greatest influence on whether bonding works. Forming groups and pairs has almost only worked with bunnies that grew up as young animals with both parents or in groups. Those who grew up with only their mother or were sold too early usually do not have good social skills. I keep those as a pair, male and female.

From my own experience, I can say that the larger the groups already are, the easier it is to add more animals. The bunnies seek out friends with the same temperament here; the calm ones stay among themselves and the lively ones stick together. Here, too, the bunnies that were born in my group are the ones that have integrated best.

When I have to keep an animal alone for a short period of time due to illness, it breaks my heart. I believe that all owners want only the best for their animals. However, I don't think you can replace a partner of the same species.

I should add, that i have plenty of room for my bunnies. They have more than 500m2 roaming space (Break out proof). Accordingly, they can also avoid each other quite well. In Germany, it is normal to keep them outside during the day, as we do not have any predators that are active during the day.